building a power supply with pc psu. possible?

[Crazy L]

Hi guys

Recently saw an article in a mag by where the journo built his own power supply by using two server psus and an ali case (you've probably read the one in question). I like things like that, and having skimmed through this and that forum, saw another couple of similar projects. However, they seemed to use server power supplies. So my question is: Is it viable to use standard PC power supplies? even if I wanted to use two to get 24v?

Any help from some you sparky types out there would be much apprec'd.

Oh, one more thing:

disclaimer - "I do not hold anyone on the rcha forum responsible for me getting a tingly arm for a couple of days due to incompetence on my part with electrical systems"

[waveydavey]

Its duty cycle and wattage, home PC supplies are just not rated at the level required for charging at 24v and mega currents. Rather than getting the tingly arm that could kill you why not take a look at a retail version or take a look at the ones coolice does, reasonable prices and the knowledge that you're not going to set fire to the house.

If you still fancy the DIY route take a look at this thread

Portable charging station - The Build Starts - Page 6 - HeliFreak

Exactly how I built mine and no earth mod to worry about

[Gixxer]

I use a 750 Watt Corsair PSU for all my charging.

Connect together the positive rails, connect a switch between the green wire and negative and you're good to go.

[xygax]

Don't use pee sea power supplies they aren't up to the job. A server supply is a lot better they have a single (and sometimes an aux) voltage out that's adjustable between about 11.7 and 13 v you will need to shed the earth on the dc on one of them and then just turn them on... for this we have a device..... its a widget for the 600w (DPS600) and that will do most chargers at full chat when configured as a pair .... some can be found here Coolice PSU's


Steve

[jimma]

sorry im sure it seems a really silly question, but what is the need for a psu power supply?

[waveydavey]

To run a charger that uses 12 or 24v and has enough capacity/grunt to run the charger at it's maximum. IE if you want to parallel charge 6S packs at more than capacity or more than 1 at a time

Here you go

[Mark_T]

sorry im sure it seems a really silly question, but what is the need for a psu power supply?

The better chargers all require a low voltage input as they were designed for easy use in the field rather than plugged into the mains power at home.

A computer PSU is generally designed to output the same low voltage so it is a good option for running these chargers when you do have higher voltage available either at home or at the field using a generator.

[Crazy L]

home PC supplies are just not rated at the level required for charging at 24v and mega currents. Rather than getting the tingly arm that could kill you why not take a look at a retail version or take a look at the ones coolice does, reasonable prices and the knowledge that you're not going to set fire to the house.

If you still fancy the DIY route take a look at this thread

Portable charging station - The Build Starts - Page 6 - HeliFreak

Exactly how I built mine and no earth mod to worry about

Price mainly, £200+ for something to supply juice to a charger seemed a bit steep in my book. I know there are cheaper but I was trying to be future proof. On the subject of why a PC psu, my local Novatech does 850w ones for £32, now, wouldn't two of those add up to 1700w?

Thank you all for the advice and links though, as no one here wants me to blow myself up (yet), I think I may follow one of the ones already done

[JoeBailey]

Hi L

I built my own psu using 2 x 1450w servor psu's, I paid £28 each posted for these. After combining them I have a 2900w @ 24v psu.

It's not hard to do but it is possible to do it wrong and blow a psu up. The servor psu's are able to cope at much higher loads then desktop psu's

Here's a pic of mineImageUploadedByTapatalk1390077154.681536.jpg

Cheers
Joe

[waveydavey]

Price mainly, £200+ for something to supply juice to a charger seemed a bit steep in my book. I know there are cheaper but I was trying to be future proof. On the subject of why a PC psu, my local Novatech does 850w ones for £32, now, wouldn't two of those add up to 1700w?

Thank you all for the advice and links though, as no one here wants me to blow myself up (yet), I think I may follow one of the ones already done

Mine cost me less than £60 and one of Ians (coolice) is around the same so no 200 quid., what is the current rating of the novatech one and the output voltage, bang the specs up and let us have a look.

Building your own isn't difficult and as long as you follow the builds and advice you're unlikely to do anyone any harm

[Crazy L]

Hi L

I built my own psu using 2 x 1450w servor psu's, I paid £28 each posted for these. After combining them I have a 2900w @ 24v psu.

It's not hard to do but it is possible to do it wrong and blow a psu up. The servor psu's are able to cope at much higher loads then desktop psu's

Cheers
Joe

Mine cost me less than £60 and one of Ians (coolice) is around the same so no 200 quid. Building your own isn't difficult and as long as you follow the builds and advice you're unlikely to do anyone any harm

Fair enough, I really am just starting to look at this albeit casually, and it seems you guys have a larger knowledge base than I originally thought before I scratched the surface by asking what may seemed like a naive question, because it was.
I'll make no bones about not really knowing what to look for, because I didn't. If pc ones were viable, I suppose you would be using them as opposed to server ones. Thank you all for your comments.

Learn a little every day.

Joe Bailey, out of curiosity, where did you get your psus from?

[JoeBailey]

Here ya go, and even cheaper then I paid.

Dell Poweredge 6850 Power Supply PSU PS-2142-1D HD435 0HD435 - Free UK P&P | eBay

I got mine from the same supplier.

Or some smaller ones with inbuilt fans.
0JX399 Dell PowerEdge 2950 750W Hot-Plug Redundant AC Power Supply Unit Z750P-00 | eBay

The intsructions can be found over on RC groups for the pinouts for loads of these PSUs

[waveydavey]

6850 is more than you could possibly need and a good choice. The post above that gives the details on the supply I built using the same ones.

[Mark_T]

my local Novatech does 850w ones for £32, now, wouldn't two of those add up to 1700w?

In short, no, you'd be lucky to get 400W out of those things at 12V and they are not built to deliver their peak power all the time so tend to quickly fail if fully loaded.

The suppliers have a habit of being a little misleading with their power ratings and they often have lower limits for each voltage delivered which they add together to justify the advertised rating.

The one you are talking about has a 36A limit for example.

Stick to server PSUs, they are properly build for the job.

[xygax]

These in pairs HP ProLiant Server 575W Power Supply Model DPS-600PB P/N 338022-001 321632-001 | eBay
will work fine and they deliver 24v at 49A.... that will drive a PL6 at max output and most other reasonable battery chargers.

Steve